Movable dam and gate



(No Modei.)

J. DU BOIS.

MOVABLE DAM AND GATE.

No. 303,825. Patented Aug. 19, 1884.

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UNITED STATES @artnr @lirica JOHN DU BOIS, OF DU BOIS, PENNSYLVANIA.

MOVABLE DAM AND GATE.

SPECXFICATION forming part of Letters Patent No. 303,825, dated August19, 1884.

Application tiled December 14, 185334 To @ZZ whom zt may concern:

Be it known that I, .IO'HN DU BOIS, of Du Bois, in the county ofClearfield and State of Pennsylvania, have invented certain Improvementsin Movable Dams and Gates, ot' which the following is a specitication.

My invention relates to that class of rising and falling dams and gateswhich consists of hinged overlapping leaves or sections, the elevationof which is effected by admitting water under pressure beneath them, asrepresented in various Letters Patent ofthe United States hithertogranted to me.

The object of the present invention is to avoid the application ofexcessive pressure beneath the dam; and to this end it consists inconstructing the overlapping edges of the leaves or sections in suchmanner that when the dam reaches the proper limit of elevation openingswill be exposed for the escape of the water between or through the edgesof the leaves,

teterring to the accompanying drawings, Figure l represents a verticalsection through a dam having my improvement applied thereto. Fig. 2 is asection ofthe same on line x x.

A represents the base or foundation of the dam, and Il (l the two leavesor sections forming the body of the dam. The leaf B is hinged at itsupstream end and overlaps the free edge of the leaf (l, which is hingedat the downstream end. Suitable gates or wickets will be provided forthe admission of-water beneath the leaves when they are to be lifted,and for permitting its escape when they are to be lowered. These gates,together with the portions of the'daiu above referred to, may beconstructed 4in the same manner as in either of the various patentshitherto granted lo me, to which reference may be made for a detaileddescription thereof. To the upper leaf, l, at or near its free edge, Iapply on the under side a series of do\\='1i\vardlypro jeeting blocks orwedges, a, which may be separated from each other to any suitable dis-ltance. During the ordinary operation of the dam, and while its elevationis within the prescribed limit, these blocks are inoperative. lVheu,however, the dam reaches the extreme elevation, the edge of the leaf C,riding beneath the blocks a, lifts the under surface of the leaf l5above the edge of the leaf (l, thus producing between the two leaves aseries of openings, b, such plainly represented in (No model.)

Fig. 2, through which the Yater may escape freely, so that theapplication of an excessive pressure within or beneath the dam becomesimpossible.

The essential feature of the improvement consists in constructing thecooperating edges of the leaves B C, in such manner that when they reachthe proper limit of elevation openings will be formed between them forthe es` cape of water. Provided this action is retained, the form of theblocks may be inedilied as desired, or in place of the blocks, reeesses, or openings may be. formed in the under surface of the leaf B,as indicated in dotted lines in the drawings.

Forthe purpose of insuring a uniform rise and fall ofthe dam at allpoints in its surface I pivot to the leaf C bars I), provided with tworacks which engage in pinions E, a. series of these pinions beingmounted on a single shaft extending lengthwise beneath the dam, as in mypatent dated July 3l, 1883, No. 282,062. The elevation of the leaf Gislimited by means of a chain, F, attached to the lower end ofthe har D,and secured to an eyebolt or other equivalent fastening in thefoundation.

The present invention is restricted to those matters and things whichare hereinafter claimed, and as to all matters which may be described orshown, but which are not claimed, the right is reserved to malte thesame the subject of a separate application.

Having thus described my invention, what I claim isl. In a rising andfalling dam, the hinged overlapping leaves provided at the overlappingedges with means of the character described and shown to permit theescape of water from beneath them.

2. In a rising and falling dam, the combination of the leaf C, theoverlapping leaf I3,

and blocks a, to cause the separation of the TOO

